Transformer.



and forming a part of this specification;

iUlii'llED STATES QFFE@ oLaXToN 1 3. ALLEN AND svnN lessenaar, or LYNN, nessnonusnrrs, AssreNons rro ernannt annusare courtier, n oosronnrroN or New roar;

TRANSFOHMEn No. 850,714. Specication of Letters Patent. atented April 16, 1907.

Application led April 211:, 1906. Serial No 313.375.

To (tI/Z whom it may concern:

Be it known that we, CLAXTON it. ALLEN, a citizen oi the United States, and SvnN it. BERGMAN, a subject oi the King ot' Sweden, residing at Lynn, in the county oi' Essex, State of Massachusetts, have invented certain new and useful Improvements in rira-nsiormers, of which the following is a specification.

. Our present invention has tor its object thc production oi" a transformer possessing eX- cellent mechanical and operating properties and which may be readily and economically constructed.

rllhe various features of novelty which characterize our invention are pointed out with particnlarity in .the claims' vannexed to formed ci'E-shaped'punchings 10 and suitable end unchings 11, as shown in Fig. 3. in assemb ing the unchings it will be understood that some oi' the punchings composing the central bundle 9 are reverse with res ect tothe lsthers, as indicated by the dotted ines in Fig. 3, so that the laminas break joints. Each bundle 8 is substantially rectangular in outline and is iormedlwith one coil-receiving window.' `The bundles 8 and 9 are assembled so that the window in one bundleS registers with one of the windows in the bundle 9 and the window in the other bundle 8, registers with the other window in the bundle ,9. rlhe bundle 8 may advantageously be composed of 'tl-shaped punchings 12 and rectangular end closing members 13., as shown in 'llig d. in order that the joints may be broken in the bundles 8, the two legs of the tS-shaped punchings are oi di'lerent lengths. ln. some oi' the punchings the narrower leg is the shorter, as shown in iull lines in F ig. 1i, while in other punchings the nar- -rower leg is the longer, as indicated by the dotted lines in Fig,4;=f The. laminae cornposing the bundles 8 .and 9 rii'ay be secured together in any suitable manner, asby rivets or` pins 1d oi' insulating` material-such as wood, hard iiber, or the likepassing through registering holes 14', formed for the purpose in the punchings.-

The ,portions of' the bundles 8 'forming a part of the central lee 2 of the core are considerably narrower than the corresponding portion of the bundle 9. Against each side oi thecentral portion ci the bundle 9, projecting by the corresponding portion ci 'the adjacent bundle 8, is placed one of the auxiliary units of the core. Asshown, each of the auxiliary units, which are identical in construction, is in general similarto the bundles 8, being composed of a rectangular bundle 1 5 of lamin, extending transversely to the laminae in the bundles 8 and 9 and having a rectangular coil-receiving window formed in it. In theconstruction shown inliig. 2 the thickness of the portion of each bundle 15 forming apart oi the central leg 2 of the core plus the width of the portion ei the corresponding bundle 8,-r`orming a part of the central leg, is Iequal to the width of the-central portion of the bundle 9. As a result thecentral leg is rectangular in cross-section. The laminae 16 and 17, composing each bundle .15 and corre- For "a better understanding oi our invention and the advantages possessed by it reierence may be had to the accompanying drawings and descriptive matter, in which we have illustrated forms in which it may be embodied.

Oi the drawings, Figure 1 is a perspective view ci a transformer-core with the windings therefor shownin dotted lines. cross-sectional plan view oi the core, taken between 'the end portions of the core. Figs. 3, et, and 5 areelevations of diiierent punchings which may be employed; and Fig. (i is a view similar to Fig, 2, showing a modiiied construction.

ln our improved transformer-core the windings shown in dotted outline in JFig. which may be in the form of concentric cylindrical coils, surround a central leg 2 of the core and are inclosed by four outer core-legs 3, 4, 5, and 6, which are parallel to each other'and to the central leg 2. Theends of the central leg are connected tothe ends of the other legs by suitable end connections 7 In forming our core we employ a main unit and two auxiliary units. The main unit of the core includes the outer legs 3 and 5 and a portion of the central leg 2 and is composed 0i two similar bundles lol' laminas S and a bundle oflarninae 9 inter osed between them. The central. bundle of -aminae is substan-` tially rectangular in outline and has formed in it two coil-receiving windows which are separated from each other by a central portion which forms apart of et the core. The bundle 9 may advantageously be Fig. 2 is a I the laimnae forming the side bun 2O of thecentral leg by interleaving in tL e outer .f tioned and arranged form highly efficient are iew in number and may be readily po- I 4Q layers of relatively narrow laminas parallel to esame sponding to the laminas 12 and i3, respectively, may be secured together by suitable rivets, of insulating material, and the main and auxiliary units may also be secured together in any suitable manner.

ln the form of our invention shown in Fic. 6 a no tch 18, rectangular in cross-section, is formed in each corner of the central leg of the core by making the Window in a ortion of (iles 8 and the auxiliary bundles 15 wider than the Window in the body of the corresponding bundles. With this arrangement the mean length of conductor surrounding a central I5 leg of given cross-sectionv may be made smaller than when the central leg is shaped as shown in Fig. .2.' In all bf the forms of our invention the outer legs of the core may die made wider than the corresponding ortions and placed one at each side of said ciantral layer, and at opposite edges thereof, and two other layers of lamins transverse to those of the central layer placed. one at each side ol the centrallayer, the thickness of each of said 4 5 other layers being equal to the difference in width between one of said relatively -wide lamin and onel of said relatively narrow laminas.

2; In a transformer, a core consisting of a 50 main unit and two auxiliary units, said auxil'iaryunits being laminated transversely to the main unit, said main unit consisting of a central bundle of lamin having two translnas one at each side of said central bundle "and each having one coil-receiving window ormed in it, the Window in one of said side bundles registering with one window in the 60 central bundle and the window in the other side bundle registering with the second window/in the central bundle, said central por` tion being Wider than the corresponding portion of the side bundles, the auxiliary units 65 being composed each of a bundle of laniinae having one coil-receiving window formed in it, said auxiliary units being arranged at opp osite sides of said main unit with the edges of the laminas 0f each auxiliary unit abutting 70 against the portion of said central portion projecting by the corresponding side bundle.

n witness whereof we have hereunto set our hands this 21st day of April, 1906 CLAXTON E. ALLEN. kil/'EN R. lBllllli/UQ.

legs-a certain amount of rectangular laminas of magnetic material. l

The `embodiments of our inventions hereinbefore described when properly proportransformers in which copper, a relatively high-priced material, and iron, a relatively ow-priced material, are economically ernployed,` The different punchingsA employed excellent mechanical properties and can be readily handled and transported. hat we claim as new, and desire to secure by Letters Patent of the United States, is-

l. .In combination, a winding, and a core portion surrounded thereby comprising a central layer of relatively wide laminas, two

Witnesses:

JonN A.l\\IoMANUs, Jr., HENRY 0. ldfns'rnnnanr.

verse coil-receiving windows separated by a 

